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150 Views
Registered: ‎03-21-2019

What if I connect JTAG chain like this?

Hi Guys,

So we all know a JTAG chain is connected like this:

Picture1.png

 

But I wonder what if I (somehow accidentally) connect this chain like this?

Picture2.png

Will this cause any problems? What would I see on the programming software (like Digilent Adept)?

 

Thanks

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Scholar drjohnsmith
Scholar
140 Views
Registered: ‎07-09-2009

Re: What if I connect JTAG chain like this?

So when the JTAG program was trying to initalise the chain,
you would have two outputs driving one input.
when both outputs are 1, u will get a 1, same when both are 0, you will get a 0.
but when one output is 1 and one is 0, your goig to get what ?
it might be a 1 , it might be a 0,

basicaly you going to get corrupted data back,

its broken